When listening or monitoring voice or code messages on a radio communications receiver, the listener often finds that a message or conversation being received is of no interest, or may even be distracting to his or her other activities. The obvious and most often used response to this distraction is for the listener to turn the volume down. The problem is that the listener will then often forget to turn the volume back up, or will not know when to turn the volume back up, so as not to miss another message of importance.
In the case of scanning receivers, another alternative for the listener to mute out an undesired conversation is by actuating the lock out feature, which subsequently skips the frequency that was carrying the distracting conversation. This results in the same problem of not knowing when to restore the frequency back to active use or forgetting that the frequency has been locked out.